<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
 <head>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <title>获取变量的布尔值</title>
<link media="all" rel="stylesheet" type="text/css" href="styles/03e73060321a0a848018724a6c83de7f-theme-base.css" />
<link media="all" rel="stylesheet" type="text/css" href="styles/03e73060321a0a848018724a6c83de7f-theme-medium.css" />

 </head>
 <body class="docs"><div class="navbar navbar-fixed-top">
  <div class="navbar-inner clearfix">
    <ul class="nav" style="width: 100%">
      <li style="float: left;"><a href="ref.var.html">« Variable handling 函数</a></li>
      <li style="float: right;"><a href="function.debug-zval-dump.html">debug_zval_dump »</a></li>
    </ul>
  </div>
</div>
<div id="breadcrumbs" class="clearfix">
  <ul class="breadcrumbs-container">
    <li><a href="index.html">PHP Manual</a></li>
    <li><a href="ref.var.html">Variable handling 函数</a></li>
    <li>获取变量的布尔值</li>
  </ul>
</div>
<div id="layout">
  <div id="layout-content"><div id="function.boolval" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">boolval</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.5.0, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">boolval</span> &mdash; <span class="dc-title">获取变量的布尔值</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-function.boolval-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>boolval</strong></span>(<span class="methodparam"><span class="type"><a href="language.types.declarations.html#language.types.declarations.mixed" class="type mixed">mixed</a></span> <code class="parameter">$value</code></span>): <span class="type">bool</span></div>

  <p class="para rdfs-comment">
   返回 <code class="parameter">value</code> 的 <span class="type">bool</span> 值。
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.boolval-parameters">
  <h3 class="title">参数</h3>
  <dl>
   
    <dt>
<code class="parameter">value</code></dt>

    <dd>

     <p class="para">
     标量值会被转化成 <span class="type">bool</span> 值。
     </p>
    </dd>

   
  </dl>

 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.boolval-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   <code class="parameter">value</code> 的 <span class="type">bool</span> 值。
  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.boolval-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-5268">
    <p><strong>示例 #1 <span class="function"><strong>boolval()</strong></span> examples</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #DD0000">'0:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">0</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'42:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">42</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'0.0:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">0.0</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'4.2:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #0000BB">4.2</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"":&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">""</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"string":&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">"string"</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"0":&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">"0"</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'"1":&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(</span><span style="color: #DD0000">"1"</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'[1,&nbsp;2]:&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">([</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">2</span><span style="color: #007700">])&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'[]:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">([])&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #DD0000">'stdClass:&nbsp;'</span><span style="color: #007700">.(</span><span style="color: #0000BB">boolval</span><span style="color: #007700">(new&nbsp;</span><span style="color: #0000BB">stdClass</span><span style="color: #007700">)&nbsp;?&nbsp;</span><span style="color: #DD0000">'true'&nbsp;</span><span style="color: #007700">:&nbsp;</span><span style="color: #DD0000">'false'</span><span style="color: #007700">).</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
0:        false
42:       true
0.0:      false
4.2:      true
&quot;&quot;:       false
&quot;string&quot;: true
&quot;0&quot;:      false
&quot;1&quot;:      true
[1, 2]:   true
[]:       false
stdClass: true
</pre></div>
    </div>
   </div>
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.boolval-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.floatval.html" class="function" rel="rdfs-seeAlso">floatval()</a> - 获取变量的浮点值</span></li>
    <li class="member"><span class="function"><a href="function.intval.html" class="function" rel="rdfs-seeAlso">intval()</a> - 获取变量的整数值</span></li>
    <li class="member"><span class="function"><a href="function.strval.html" class="function" rel="rdfs-seeAlso">strval()</a> - 获取变量的字符串值</span></li>
    <li class="member"><span class="function"><a href="function.settype.html" class="function" rel="rdfs-seeAlso">settype()</a> - 设置变量的类型</span></li>
    <li class="member"><span class="function"><a href="function.is-bool.html" class="function" rel="rdfs-seeAlso">is_bool()</a> - 检测变量是否是布尔值</span></li>
    <li class="member"><a href="language.types.type-juggling.html" class="link">类型转换的判别</a></li>
   </ul>
  </p>
 </div>

</div></div></div></body></html>